Illuminating device.



A. W. BEUTTELL.

ILLUMINATING DEVICE.

APPLICATION rlLnn PR. 17, mos.

Patented Aug. 18, 1914.

ALFRED WILLIAM BEUTTELL, on NEW YORK, N. Y.

ILLUMINATING DEVICE.

onaco.

Specification of Letters Patent.

atented Aim. 1 8, 1914.

Application filed April 17, 1908 Serial No. 427,667.

To allwhom it may concern:

Be it known that I, Amnno W. BEU'I'IELL, a subject of the King of GreatBritain, and a resident of the borough of Manhattan of the city of NewYork, in the county and State ofv New York, have invented certain newand useful Improvements in Illuminatin Devices, of which the followingis a speci cation, reference being bad to the accompanying drawings,forming a part hereof.

The invention relates more particularly to improvements in parabolicreflectors and to their use in connection with double-ended incandescentlamps or lamps having substant'ially straight filaments, the generalobject being to provide an illuminating device in which the lightdeveloped may be under absolute control and may be most effectivelyutilized or distributed.

The reflectors employed in accordance with the invention have a long andcontinuous reflecting surface which is substantially parabolic in crosssection and the lamps are mounted so as to extend along this surface ina straight line with their filaments substantially coincident with thefocal line thereof.

In the employment of my improved illuminating device for the purpose oflighting different objects such as pictures, bookcases, etc, it ispossible to obtain uniform lighting effects which in most cases are muchto be desired. For this purpose I preferably place an illuminatingdevice at one end of the picture, case or other article to beilluminoted and make the side of the reflector which is nearest orclosest thereto shorter than the other side. In this way, and by lacingthe reflector at such an angle that Its principal axis will cut theother end of the article to be illuminated, I so distribute the directand reflected illumination that the direct illumination will bereinforced by the reflected illumination at the points most requiringit, or in other words, as will be seen more particularl hereinafter u)on reference to the drawing, combine the direct and reflected rays toproduce a uniform illumination. In still other cases, it is desirable toconcentrate the light from 'the illuminating device upon a particularobject or space and yet to avoid any harp definition between theilluminated portion of the object or space and the non-illuminatedportion adjacent thereto, and for this purpose I modify the parabolicsurface by bending the edges thereof inwardly to a slight extent andthereby causing some of the rays from the device to be slightlydivergent and producing a diffusion of light around the central portionor nucleus;whereby there is no sharp contrast between the illuminatedand the non-illuminated portions of the article liflffl'llll to Fi s. 1and Lit will be seen.

h I" l that the reflector o. consists of an elongated or extendedtrmigh-shaped device substantially parabolic in cross section andpresenting a continuous reflecting surface. It may be constructed fromany suitable material and in any suitable manner although for mostpurposes it is preferable to construct the reflector from sheet v metaland to bend the edges over as illustrated at b and in order to formbeads to receive the conducting wires of the external supply circuit.The lumps r! are of the double-ended variety each having a substantiallystraight filament c and being preferably of the well known Linoliteconstrluztion. The ends of the lam) are received in supporting socketsthe latter being provided with contact pieces r which are connected withthe feed wires in the heads I) and c in such a way that the contactpieces in adjacent sockets are electrically connected with opposite feedwires, thus establishing a circulation through each lamp. When mountedin the sockets these lamps'are arranged in a straight line within thereflector with their filaments extending along the focal line or axis-ofthe reflector,

' this line being the line connecting the foci of the parabolas formedby cutting the reflector transversely at any point.

It will be obvious that different conditions will determine the preciseshape and size of thc reflector aside from its parabolic properties. InFig. 3, for instance, where it is shown diagrammatically in relation toa picture to be lllllllllllfllfitl, the side of the reflector which isnearest or closest to the ever that the main axis of the reflector cutsthe picture near the other end thereof so that the most intense portionof the reflected light will he directed upon said other end of thepicture.

It was stated at the outset of this specification that the inventionrelated particularly to the use of parabolic reflectors in connectionwith incandescent lamps having substantially straight filaments, andWhile most oi the features of the invention have been developed withsuch a lamp in View, many of the improvements are not inconsistent withthe employment of a different kind of lamp and-particularly a differentkind of tubular lamp. The improvements are not limited therefore toemployment in connection with straight filament lamps, as in some casesit will be advantageous to em ploy the improved reflectors in connectionwith other forms of lamp. Many other changes, modifications andvariations may he made in the embodiment of the present improvementswithout departing from the invention.

- I claim as my invention:

1. The combination with an object to. be illuminated, of an elongatedreflector of substantially parabolic form in cross section, one side ofsaid reflector being located close to one edge of the surface to he illnminated and the principal axis of the reflector intersecting thatportion. of the surface to be illuminated which is remote from thereflector, and an incandescent lamp filament section in alinement withthe focal axis of the reflector.

2. The combination of an object or surface to be illuminated and meansfor illuminating the same, which means is provided with an elongatedreflector of substantially parabolic form in cross section, one side ofsaid reflector being located close to one edge of the surface to beilluminated and the principal axis of the reflector intersecting thatportion of the surface to be illunimated which is remote from thereflector.

This specification signed and witnessed this 7th day of April A. .D.,1908.

ALFRED WILLIAM BEUTTELL.

Signed in the presence ofn LUCIUEI E. VARNEY, HOMER H. Snow.

